In order for political discourse to have any meaning or value, there have to be certain agreed upon facts that serve as a foundation for the dialogue. But as the McClatchy piece notes, that foundation is no longer stable -- conservatives frequently choose to believe versions of events that aren't real, because the make-believe version makes them feel better.
The result is an American history in which every era can be distorted to satisfy the far-right ego. Indeed, it continues to apply to more contemporary events -- tell the typical Republican that Ronald Reagan raised taxes in six of his eight years in the White House, and he/she will probably look at you as if you've lost your mind. That is, in fact, what happened, but the right chooses to reject this history, because they don't like it. (Tell these same Republicans that Barack Obama's health care plan is in line with what moderate Republicans have supported for years -- and that the individual mandate was actually a GOP idea -- and you'll get the same reaction, even though it's true.)
For all the talk about getting reasonable people with different ideologies into a room to find common ground on a host of complex issues, it's worth remembering that for many political actors in 2010, there isn't even agreement on the basics. When dealing with a large group of influential conservatives who believe FDR created the Great Depression, Theodore Roosevelt was a socialist, and Joe McCarthy was a hero, what's there to talk about?
It reminds me of the Seinfeld episode where George Costanza struggles to come up with a snappy comeback, and this is the best he can muster: